#brownells

The Colt XM177 series was a family of short-barreled carbines developed during the Vietnam War as a more compact alternative to the standard M16 rifle. These carbines, designed for U.S. special operations forces, were developed in the mid-1960s and became a precursor to modern military carbines such as the M4. The most notable variants were the XM177 and XM177-E2, which were used by special forces units, including the U.S. Army’s MACV-SOG and other elite groups.

The U.S. military’s experience in Vietnam highlighted the need for a more maneuverable firearm that could still provide the firepower of the M16 but in a more compact form. The Colt XM177 series originated from earlier efforts to shorten the M16 rifle, particularly the CAR-15 project, which included a variety of weapons based on the Armalite AR-15 platform. Colt's first attempt at a carbine version of the M16 was the Model 607, which was part of the Colt Automatic Rifle-15 (CAR-15) family. However, this model had issues with reliability and an awkward collapsible stock.

By 1966, Colt refined its carbine design into what became the Colt Model 609 (XM177-E1) and Colt Model 610 (XM177). The primary difference between these models was that the XM177-E1 was designed for the Army, while the XM177 was intended for the Air Force. These carbines featured a 10-inch barrel and a unique moderator that functioned both as a flash suppressor and a rudimentary sound suppressor.

The XM177-E1 (Colt Model 609) was issued mainly to U.S. Army special forces. It included a two-position retractable aluminum stock, allowing for a compact design ideal for jungle warfare and airborne operations. The barrel length was significantly shorter than the 20-inch barrel of the standard M16A1, making it easier to handle in tight quarters. The carbine was chambered for 5.56×45mm NATO and had a forward assist—a feature absent on the Air Force's XM177 (Colt Model 610) variant.

Due to feedback from field use, Colt modified the design into the XM177-E2 (Colt Model 629). The major improvement was a slightly longer 11.5-inch barrel, which improved reliability and accuracy while still maintaining a compact size. The longer barrel also allowed for better ballistic performance and reduced muzzle flash. Additionally, the XM177-E2 featured a redesigned sound moderator to further suppress noise and muzzle blast, helping with concealment and reducing the risk of enemy detection during covert operations.

The XM177-E2 became the most widely used version and was favored by U.S. Army special operations forces. Despite its improvements, it was never standardized as an official U.S. military rifle designation beyond the experimental "XM" classification. However, many were issued to MACV-SOG operatives, Long Range Reconnaissance Patrol (LRRP) units, and other special operations forces engaged in close-quarters combat in Vietnam.

The XM177 series was well-liked for its maneuverability and high rate of fire, making it a formidable weapon in jungle warfare and for airborne troops. However, the short barrel resulted in: Increased muzzle blast and flash, despite the presence of the moderator. Reliability issues due to increased cyclic rate and fouling of internal components. Moderate suppression from the moderator, which was not a true silencer but helped reduce the carbine’s loud report.

Additionally, the moderator was classified as a sound suppressor by the Bureau of Alcohol, Tobacco, and Firearms (ATF), leading to legal restrictions on civilian sales in later years.

Though the XM177-E2 was never fully adopted as a standard-issue rifle, it directly influenced the development of future military carbines. The Colt Model 653 and later the M4 Carbine, which became the standard-issue carbine for the U.S. military, owe much of their design to the XM177 series.

The lessons learned from the XM177 series were crucial in developing modern compact rifles, particularly in balancing barrel length, reliability, and modularity. Today, while original XM177 models are rare and primarily collector’s items, their impact on military firearms design remains significant.

I have been a huge fan of the .300 Blackout cartridge! For anyone that’s actively in the suppressor game, a rifle cartridge like the .300 Blackout is a no brainer. Yes I do realize that many pistol calibers can be ran subsonic in AR style rifles and pistols, but the .300 Blackout shares all of the common parts of its 5.56 counterpart except the barrel of course. This makes the .300 Blackout make much more sense than a pistol caliber AR that uses a bunch of different parts and more chance of not running correctly. Late last year I cobbled together yet another .300 Blackout from some parts I had leftover form previous projects and picked up the remaining needed parts from Brownells. My Brownells BRN-180 .300 Blackout has been one of my favorites as well. This makes the 4th .300 Blackout I own, so there’s no mistaking that I’m a fan of the caliber. But is it still the KING? 

In the past few years there’s been a number of other newer calibers coming into the market that are kinda following in the .300 Blackout’s footsteps. One of those is the 8.6 Blackout caliber that was developed by Q. This is of course a larger .338 diameter projectile than the .300 diameter projectile used in the .300 Blackout. The parent case is also that of the 6.5 Creedmoor. Barrel wist rates are considerably different as well. Most .300 Blackout are 1:8 twist and the 8.6 Blackout is a 1:3 twist rate to get the most out of the shorter barrels and heavier projectiles. The 8.6 Blackout’s advantage is the availability of much larger weight projectiles and therefore a more devastating effect on the intended target. The disadvantage in my opinion is the need to use an AR-10 sized receiver increasing the overall weight of the firearm. There’s no free lunch as they say, so you can’t gain something without giving up something else. And if you think that .300 Blackout ammunition is pricey, you’ve not taken a look at the 8.6 Blackout yet. But wait there’s even another newer cartridge on the horizon that claims to beat out both the .300 Blackout and the 8.6 Blackout. 

Introduced by Hornady is the new .38 ARC which is supposedly bale to deliver over one and a half times the energy of the .300 Blackout. Once again the advantage of this particular caliber is the ability to load with bullets much heavier than .300 Blackout. With over 300 grains on tap, the .338 ARC eclipses the maximum 225gr loads of the .300 Blackout by a huge margin. The .338 ARC uses the same pattern magazines and bolt as the 6.5 Grendel and doesn’t require the use of the larger frame AR-10 receiver to run. This is literally the best of both worlds with subsonic performance of the .300 Blackout, 1.5X the energy and the ability to maintain a similar weight of the firearm. Since the .338 ARC is totally new, only time will tell how much it takes off. As expected the ammunition is out of this world expensive at the moment, but if popularity takes off, expect the prices to come down a bit once supply matches demand. 

So is .300 Blackout still the subsonic king? I’d say for now due to the popularity and availability of the caliber, but be on the look out for these 2 other new calibers, especially the .338 ARC. Brownells has you covered on all 3 of these calibers if you’re looking to pick one up. 

Alright guys it’s been a while but I felt like this one be a good subject to post on. Before getting starting I do have a full video on my YouTube channel showing everything I am talking about in this post.

Recently I got the urge to set up a “spr” style rifle. I’ve always thought the idea of taking a standard “infantry” style rifle and giving it a little longer barrel and a bit more magnification. That being said I had what I think is the perfect candidate for this. Last year solgw sent out one of their exo3 16” complete uppers for me to use and review. That I think is the perfect base to start with. To go with that I have a brownells Mpo 1-6 optic sitting in a Midwest industries qd mount. While I do want to eventually switch this out for a little bit more magnification with something like the leupold mk4. Then the Harris bipod is a key feature of this rifle. The lower is just my typical Anderson stripped lower that I then fill with all the forward controls designs parts and a geissele trigger. The thing that I think is important with this rifle is still keeping the ability to do regular rifle things. To do that we have all the regular rifle accessories like the streamlight vir2 for the ir laser, modlite okw hooked to a Unity hot button, and having the griffin reece 5 to keep it suppressed.

I just recently finished getting this all together and got to take it out for a few hundred rounds. So far I’ve just been getting my bearings since it has been a while since I’ve shot at any actual distances. After zeroing the rifle I began taking shots and doing 1 up drills at ranges varying from 100 yards up to 236 yards today. It’s somewhat difficult to find shots in my woods where I can see my steel plates through the woods. So far though this thing has been a blast to shoot and run. Definitely stay tuned to keep up on what’s going on with this mini series. I plan on focusing a lot of the time I put into my content on just this single project so things will be moving pretty fast.

Thanks for reading

A Look at the additional additions and details of my Retro-Mod Rifle.

The idea of retro-mod rifles have really exploded in the last couple of years. Be it for nostalgia, or to make a clone of the equipment used by military or law enforcement of mentioned eras gone by with tasteful modern additions, it’s a market people are interested in. Brownells used this idea of Retro inspired modern rifles with the BRN180. A modern take on a classic. Their vision of what the AR180 would have evolved into, had that platform had the popularity of the AR15. It might seem sorta backwards on this concept, but my idea was to be able to take a platform based of a rifle I wanted and couldn’t afford, and give it the retro styling cues to fill that void. The BRN180 filled the void and need of an AR180, and here are the accessories I used to give my rifle the look I wanted.

“Retroing” a Modernized Idea

Well start with stock. Brownells offers an AR180 style stock that is a nice looking piece. But when Midwest Industries released their AR180 style stock, that featured a trapdoor it was the one I had to have for this rifle.

The Trapdoor and contents I’ve chosen to carry.

Packaged and sold by Midwest Industries, this stock is a joint venture between MI and Manticore Arms. Per the specs supplied by MI on their website, the trapdoor stock features the main body made of a fiber reinforced polymer. The length of pull with a 1913 adapter to an AR15 lower is the same as the original AR180s. The trapdoor as seen above will hold a standard M16 cleaning kit and a small bottle of CLP. The only downside to the trapdoor is, it is advertised as not water-tight, and they suggest if you have something you want kept completely dry during a dunking event, put it in a bag. I haven’t tested it that hard in rain yet, but that is something I have the intent to do in the future.

The Midwest hinge, attached to a KNS adapter for AR15s

The hinge is made by Midwest. Made from 4140 heat treated steel, it attached nicely via 1913 rail to the KNS adapter I have in place of the buffer tube in the UnBranded AR lower I use, and has a nice spring and lockup when in the ready position.

Next up is the optic I chose. The original AR180 scopes used were a 4x, that looked very similar to the carry handle scopes of that day. I opted to go with a Primary Arms GLx 2x prism scope. One thing I love about the PA optics is the ACSS reticle, and this scope to me was a modern update that flowed with the overall mix of modern and retro I was going for. The only thing I’m going to add to the scope, will be a QD adapter. That way getting to the Magpul Gen 3 BUIS will be quick and easy.

The sling is a USGI M16 sling, attached to an A1 grip the same way it was on the M16, and attached to the MLok rail via a GI style MLok sling adapter just in front on the handguard.

And now to what has become my favorite accessory to this awesome rifle.. the Handguard. The part that gives this rifle alot of its retro looks, while keeping the hand protect form heat sustained from rapid fire. The MLok floated handguard is nicely made on the BRN, by Midwest Industries, but when firing a lot of consecutive shots, mag after mag, it heats up. This handguard remedies that. Made and sold by AR180parts.com, it is 3D printed from heat resistant ASA filament. When it comes it’s in two pieces. It’s constructed in a way, that it slides over the rail and is secured via MLok. You can see the faint line where the two pieces meet up. When it comes it also has the layer lines prominent. I ended up researching, and discussing it with the manufacturer, to ultimately “weld” (glue) the two pieces together. I then painstakingly water sanded the layer lines out, using paper ranging from 180-2500 grit in steps, giving it the slick look that Vintage M16 and AR180 handguards have. These come in 3 different lengths, from short all the way to a full rail length. Mine is the AR16 inspired handguard.

Overall this rifle is easily becoming one of my favorites. The addition of the accessories I chose, I feel gave it the more retro vibe I was seeking with modern materials, reliability, and features. If you have any interest in the stuff pictured, Check out Brownells for the BRN180 upper, stock and BUIS; Primary Arms for the GLx 2X Prism; and AR180parts.com for the handguard. I’ll link them below.

Throwback to my first AK

@brownellsinc